The present invention relates to a tissue retrieval assembly for holding and dissecting bodily tissue. More particularly, the present invention relates to a disposable instrument useful for laparoscopic procedures. The disposable instrument has a basket for holding tissue and a cutting element for dissecting held tissue. Tissue samples out away by the disposable instrument can be optionally held in a tissue trap container.
Laparoscopic surgery can be effectively used for removal of gall bladders, ovaries, tumors, or other body organs or tissues found in the abdominal cavity. Commonly, a cutting instrument attached to an end of a cannula is used to excise tissue. The excised tissue is then immediately sucked up through the cannula for disposal as medical waste. Alternatively, excised tissue can be grasped or held by tweezers, pincers, or other similar medical devices, and pulled out through a cannula inserted into an abdominal cavity through a laparoscopic puncture.
However, medical devices constructed for the practice of the foregoing tissue retrieval methods are not always suitable for retrieving relatively large bits of tissue, and/or small organs. Excised bits of tissue can be lost or move away from the operating site before they are sucked, grasped or pulled through a cannula. In addition, larger bits of tissue and small organs will not fit in one piece through the small diameter cannula used in laparoscopic procedures. Since the cannula diameter should be minimized to reduce patient trauma, simply providing larger cannula is not desirable.
The present invention provides an apparatus for retrieval of small organs and tissue from a patient's body. Tissue is dissected and removed from a patient with the aid of an instrument that includes a collapsible basket formed to define a basket cavity to contain tissue. Optionally, an anvil is attached to the basket to form an impacting surface. The basket can be collapsed to allow insertion of the collapsible basket into, and withdrawal from, a patient's body.
A cutting cannula, formed to define a cutting cannula cavity, is positioned to be reciprocatingly movable to pass through the basket cavity and impact the anvil. In operation, the cutting cannula is manually and reciprocatingly driven to pass into and through the basket cavity, cutting any tissue contained in the basket cavity. The cut tissue is then withdrawn from the patient and saved for analysis or disposed of as medical waste.
In preferred embodiments, the collapsible basket includes a plurality of flexible members. Each flexible member has a first and a second end and is prestressed to define an arcuate shape between its first and second ends. The first end of each flexible member is attached to a support tube positioned to surround the cutting cannula, and the second end of each flexible member is attached to the anvil. With this attachment arrangement the anvil is supported and the basket cavity is defined between the support tube and the anvil.
In preferred embodiments, a shield tube is positioned to surround the support tube, and the shield is movable forward over the basket to straighten and effectively collapse the flexible members forming the basket. Withdrawal of the shield tube from contact with the flexible members allows recovery of their arcuate shape and reformation of the basket cavity.
In another preferred embodiment, the cutting cannula is reciprocatingly moved with the aid of a support tube attached to hold the basket, a handle attached to the support arm, and a lever arm attached to the cutting cannula. The lever arm is biasingly connected to the handle (typically by a hinge/spring system) so that operational movement of the lever arm relative to the handle moves the cutting cannula toward the anvil. A biasing element, such as a spring, is connected to move the lever arm away from the handle to encourage reciprocating motion of the cutting cannula. The cavity of the cutting cannula is attached in fluid connection to a vacuum source.
The present invention also encompasses a method for dissecting and removing tissue from a patient's body. The method includes the steps of entrapping tissue in a collapsible basket formed to define a basket cavity, providing an anvil attached to the basket, and cutting tissue trapped in the basket by reciprocating motion of a cutting cannula, the cutting cannula being movable to pass through the basket cavity and impact the anvil, cutting any tissue contained in the basket cavity. Any cut tissue is contained in the cutting cannula cavity is withdrawn for analysis or disposal.